The bid to become the first team in Europe to win the Champions Cup five times has ended in disappointment for Leinster as Saracens regained the title they lost to the Blues a year ago.

Leinster knew they were facing into their toughest challenge since claiming the crown for the fourth time in Bilbao last May, and so it proved as Sarries overturned a 10-0 deficit, keeping the province scoreless for 46 minutes at St James' Park.

After four previous final appearances produced four victories, Leo Cullen and his players will look back on some misssed opportunities in Newcastle.

Not realising the clock had ticked into the red for half-time, Luke McGrath failed to kick for touch to end the half and Sarries responded with a converted try to level it up.

In the 47th minute, Garry Ringrose spurned a four on two overlap and a certain try to try to go it alone. It proved a crucial moment.

Earlier, midway through the first half, Jordan Larmour raced clear but just wasn't able to pick up the ball at speed and the chance was lost.

In contrast, Sarries - the 2016 and '17 champs - made the most of their opportunities and Europe's form team this season - this was their ninth win out of nine in the competition and deserved their victory, having taken out Munster already in the semis.

Until Billy Vunipola's converted try in the 66th minute, the game was still very much in the melting pot and, until then, it was a fascinating contest between the two best club sides in the northern hemisphere.

Sarries knew from early on that ref Jerome Garces wasn't going to tolerate any flaunting of the offisde rule - Billy Vunipola was pinged in the third minute for such an offence and, from just inside the Saracens' 10 metre line, Johnny Sexton's penalty put Leinster ahead.

The province showed real intent early on in the battle of the breakdown, where Sarries often assert dominance, but Mark McCall's side looked threatening with ball in hand and it took a crucial Rob Kearney tackle to deny Liam Williams in the corner.

A Ringrose knock-on in midfield was an unforced error but it wasn't an isolated incident as both teams looked nervous in front of the 51,930 sell-out crowd.

Larmour showed off his electrifying speed in the 13th minute to burn Sean Maitland on the outside and, had he collected the loose ball, he would have scored the game's opening try.

But he couldn't, and Sarries were off the hook.

Leinster themselves had a let-off in the 20th minute when, with Sarries rumbling close to their opponent's try-line, Brad Barritt charged into the ruck and barged Scott Fardy with his shoulder. Garces gifted Leinster a penalty.

A brilliant Kearney break took him through a gap that just opened up but the full-back was stopped just short by Ben Spencer, then James Lowe was denied by Liam Williams.

However the pressure took a heavy toll on Sarries, who were forced to replace both props - Mako Vunipola and Titi Lamositele- because of injury, and just as Itoje was sent to the sin-bin for straying offside twice during the Leinster attack.

With two new props on the field and Itoje off it, Sexton turned down the penalty under the posts for a scrum and Tadhg Furlong, making his 100th Leinster appearance, barrelled over for a 33rd minute try that was converted by his skipper.

Sarries needed to get points on the board before the break. They did just that - and then some.

Pressing from the restart, they were at first frustrated as Fardy won a penalty on his own 22 and Sexton cleared.

But the Premiership side came again and replacement prop Vincent Koch followed up a big George Kruis tackle on Sexton by winning a penalty and Farrell split the posts.

There was just enough time to restart and Sarries made the most of it as McGrath was punished for not kicking for touch.

Farrell kicked a penalty from his own half into Leinster's 22 and although they were unable to get over under the posts, the out-half's clever flicked pass to Maitland gave the Scotland winger a free run to the try line.

Farrell's conversion squeaked just inside the near post and it was all square as the players walked down the tunnel.

Sarries, however, were sluggish at the start of the second half and there were opportunities for Leinster to take advantage.

Sexton kicked a penalty to the corner but Kruis produced a big steal for his team.

Then Ringrose had men outside him but chose to go it alone - and while Cian Healy almost salvaged the situation, ultimately Williams came up with a superb turnover penalty on Ringrose, and the danger passed.

By now Sarries were fully awake again - the sight of Itoje practically relieving James Ryan of his no 5 shirt confirmed it - and Jackson Wray's break brought them back into Leinster's 22.

Both Will Skelton and Itoje both came close to a try but Farrell and his team had to be content with three points and not seven, but with the added bonus of Fardy in the bin for offside.

The men in red sensed blood and, while Itoje might have been fortunate not to see yellow again for a high challenge on Kearney on the hour, Sarries struck the killer blow six minutes later.

With Fardy still off the pitch, Saracens turned down a penalty in front of the posts for a scrum and it proved the right decision as Vunipola exploded off the back and somehow touched down despite the attentions of four defenders.

Farrell's conversion gave Sarries breathing space and, in truth, they easily managed to keep their rivals at arm's length for the remaining quarter of an hour.

And now Leinster must regroup quickly as Munster await in the PRO14 semis at the RDS next weekend.